Search results for " niche"
showing 10 items of 252 documents
6091Chronic heart failure is associated with inflammatory deterioration of the bone marrow vascular niche
2019
Abstract Introduction Inflammation plays a crucial role in many aspects of cardiovascular disease. Particularly, acquired mutations of hematopoietic stem cells (HSC) leading to clonal expansion of inflammatory cells (CHIP) are increased with age and are associated with an enhanced risk of cardiovascular disease. The bone marrow (BM) vascular niche plays a crucial role in maintenance and regulation of HSC functions. Previous studies in mice showed the reduction of a specific Endomucin-high (H-type) endothelial cells (EC) subpopulation by aging. However, the impact of cardiovascular disease is unclear. Therefore, we aimed to investigate the effects of age and heart failure (HF) on the vascula…
Extracellular membrane vesicles as a mechanism of cell-to-cell communication: advantages and disadvantages.
2014
Microvesicles represent a newly identified mechanism of intercellular communication. Two different types of microvesicles have been identified: membrane-derived vesicles (EVs) and exosomes. EVs originate by direct budding from the plasma membrane, while exosomes arise from ectocytosis of multivesicular bodies. Recent attention has focused on the capacity of EVs to alter the phenotype of neighboring cells to make them resemble EV-producing cells. Stem cells are an abundant source of EVs, and the interaction between stem cells and the microenvironment (i.e., stem cell niche) plays a critical role in determining stem cell phenotype. The stem cell niche hypothesis predicts that stem cell number…
Czy Nysius huttoni (Hemiptera: Heteroptera: Lygaeidae), gatunek obcy dla Europy, może mieć w Polsce sprzyjające warunki do bytowania?
2020
Nysius huttoni, the species endemic to New Zealand, is regarded as a pest which feeding can seriously reduce crop establishment in forage brassicas. It was discovered for the first time in Europe in 2002 (the Netherlands) and has spread in several European countries (Belgium, France, United Kingdom, Germany). Although detailed data on the natural spread of N. huttoni is lacking, it can theoretically be transported over long distances with infested plants, and is often found on apple and kiwi fruit packages exported from New Zealand. The species was hitherto not reported from Poland, therefore its potential geographic distribution was modelled using maximum entropy (Max-Ent) in order to pred…
Cost of host radiation in an RNA virus.
2000
Abstract Although host radiation allows a parasite to expand its ecological niche, traits governing the infection of multiple host types can decrease fitness in the original or alternate host environments. Reasons for this reduction in fitness include slower replication due to added genetic material or modifications, fitness trade-offs across host environments, and weaker selection resulting from simultaneous adaptation to multiple habitats. We examined the consequences of host radiation using vesicular stomatitis virus (VSV) and mammalian host cells in tissue culture. Replicate populations of VSV were allowed to evolve for 100 generations on the original host (BHK cells), on either of two …
Disparate movement behavior and feeding ecology in sympatric ecotypes of Atlantic cod
2021
Abstract Coexistence of ecotypes, genetically divergent population units, is a widespread phenomenon, potentially affecting ecosystem functioning and local food web stability. In coastal Skagerrak, Atlantic cod (Gadus morhua) occur as two such coexisting ecotypes. We applied a combination of acoustic telemetry, genotyping, and stable isotope analysis to 72 individuals to investigate movement ecology and food niche of putative local “Fjord” and putative oceanic “North Sea” ecotypes—thus named based on previous molecular studies. Genotyping and individual origin assignment suggested 41 individuals were Fjord and 31 were North Sea ecotypes. Both ecotypes were found throughout the fjord. Seven …
An individual-based dataset of carbon and nitrogen isotopic data of Callinectes sapidus in invaded Mediterranean waters
2022
The characterisation of functional traits of non-indigenous and invasive species is crucial to assess their impact within invaded habitats. Successful biological invasions are often facilitated by the generalist diet of the invaders which can modify their trophic position and adapt to new ecosystems determining changes in their structure and functioning. Invasive crustaceans are an illustrative example of such mechanisms since their trophic habits can determine important ecological impacts on aquatic food webs. The Atlantic blue crab Callinectes sapidus is currently established and considered invasive in the Mediterranean Sea where it has been recorded for the first time between 1947 and 19…
Osteogenic commitment and differentiation of human mesenchymal stem cells by low‐intensity pulsed ultrasound stimulation
2018
Low-intensity pulsed ultrasound (LIPUS) as an adjuvant therapy in in vitro and in vivo bone engineering has proven to be extremely useful. The present study aimed at investigating the effect of 30 mW/cm(2) LIPUS stimulation on commercially available human mesenchymal stem cells (hMSCs) cultured in basal or osteogenic medium at different experimental time points (7d, 14d, 21d). The hypothesis was that LIPUS would improve the osteogenic differentiation of hMSC and guarantying the maintenance of osteogenic committed fraction, as demonstrated by cell vitality and proteomic analysis. LIPUS stimulation (a) regulated the balance between osteoblast commitment and differentiation by specific network…
Early Cambrian origin of modern food webs: evidence from predator arrow worms.
2007
7 pages; International audience; Although palaeontological evidence from exceptional biota demonstrates the existence of diverse marine communities in the Early Cambrian (approx. 540-520 Myr ago), little is known concerning the functioning of the marine ecosystem, especially its trophic structure and the full range of ecological niches colonized by the fauna. The presence of a diverse zooplankton in Early Cambrian oceans is still an open issue. Here we provide compelling evidence that chaetognaths, an important element of modern zooplankton, were present in the Early Cambrian Chengjiang biota with morphologies almost identical to Recent forms. New information obtained from the lowermost Cam…
Osteopontin shapes immunosuppression in the metastatic niche.
2014
Abstract The matricellular protein osteopontin (OPN, Spp-1) is widely associated with cancer aggressiveness when produced by tumor cells, but its impact is uncertain when produced by leukocytes in the context of the tumor stroma. In a broad study using Spp1−/− mice along with gene silencing in tumor cells, we obtained evidence of distinct and common activities of OPN when produced by tumor or host cells in a spontaneously metastatic model of breast cancer. Different cellular localization of OPN is associated with its distinct activities, being mainly secreted in tumor cells while intracellular in myeloid cells. OPN produced by tumor cells supported their survival in the blood stream, wherea…
Long-term competitive dynamics of two cryptic rotifer species: diapause and fluctuating conditions.
2015
Life-history traits may have an important role in promoting species coexistence. However, the complexity of certain life cycles makes it difficult to draw conclusions about the conditions for coexistence or exclusion based on the study of short-term competitive dynamics. Brachionus plicatilis and B. manjavacasare two cryptic rotifer species co-occurring in many lakes on the Iberian Peninsula. They have a complex life cycle in which cyclical parthenogenesis occurs with diapausing stages being the result of sexual reproduction. B. plicatilis and B. manjavacasare identical in morphology and size, their biotic niches are broadly overlapping, and they have similar competitive abilities. However,…